Drilling apparatus

ABSTRACT

A downhole fluid powered motor and a drill bit are connected to the lower end of the drill string. The outer housing of the motor and the body of the bit are connected together and to the drill string for rotation therewith. The drill bit includes a discshaped cutter wheel that is mounted on the drill body for rotation around a transverse axis that is perpendicular to the axis of rotation of the drill string. Power provided by the motor rotates the cutter wheel around the transverse axis when drilling mud is pumped down the drill string.

United States Patent Jones [541 DRILLING APPARATUS [72] Inventor: Kenneth W. Jones, Shreveport, La. [73] Assignee: l-1yca1og,lnc., Shreveport, La. [22] Filed: Oct. 14, 1970 [21] Appl. No'.: 80,633

[52] US. Cl ..l75/l06, 175/329 [51] Int. Cl E2111 3/12, E21b 9/36 [58] Field of Search ..l75/l06, 92, 62, 173, 102,

[4 1 Oct. .3, 1972 57 ABSTRACT A downhole fluid powered motor and a drill bit are connected to the lower end of the drill string. The outer housing of the motor and the body of the bit are connected together and to the drill string for rotation therewith. The drill bit includes a disc-shaped cutter wheel that is mounted on the drill body for rotation around a transverse axis that is perpendicular to the axis of rotation of the drill string. Power provided by the motor rotates the cutter wheel around the transverse axis when drilling mud is pumped down the drill string.

8 Claims, 2 Drawing Figures [56] V References Cited UNITED STATES PATENTS 2,497,144 2/1950 Stone ..l75/l07 1,753,339 4/1930 Hencken ..l75/107X 1,877,225 9/1932 Capeliuschnicoff...175/107X 1,388,496 8/1921 Wadsworth ..l75/318 1,412,430 4/l922 Verneull ..175/107X PATENTEDncr 3 m2 FIG] Knneth W Jbnes INIVENTOR swig a; W

ATTORNEYS DRILLING APPARATUS This invention relates to drilling apparatus generally and in particular to drilling apparatus that includes a drill bit wherein at least part of the power for the cutting action of the drill bit is furnished by something other than rotation of the drill string to which the drill bit is attached.

In disc-type bits the cutter wheel of the bit is usually mounted to rotate around an axis that is transverse the axis of rotation of the body of the bit and the drill string. Rotation is imparted to the disc, at least in part, by mounting the cutter or cutters either askew, i.e., at

an angle to the direction the hole is being drilled, or off center from the axis of rotation of the bit, or both.

It is an object of this invention to provide a disc-type drilling bit wherein the disc or cutting wheel of the bit is rotated by a force other than the reaction of the cutter against the bottom of the hole as it is rotated by the drill pipe.

It is another object of this invention to provide a disctype drill bit having a positively rotated cutter wheel and one that is rotated independently of the rotation of the pipe.

It is another object of this invention to provide a drill bit having a cutter wheel that operates against the bottom of the hole to cut through the earth in the manner of a grinding wheel or milling cutter to thereby obtain the most efficient cutting action by the wheel.

It is another object of this invention to provide a drill bit having a cutter wheel that rotates in a plane that includes the central longitudinal axis of the hole it drills.

It is another object of this invention to provide a drill bit having a disc-type cutter wheel the periphery of which carries an abrasive material, such as diamonds, that is rotated against the bottom of the hole in the manner of a diamond grinding wheel to obtain the efficient cutting action of such a cutting wheel in a drilling operation.

It is an object of this invention to provide an improved diamond bit wherein the entire surface of the bit that contains the diamonds for cutting purposes moves across the bottom of the hole at a relatively uniform speed.

It is also an object of this invention to provide an improved disc-type diamond bit in which the diamond cutting surface moves alternatively into and out of engagement with the bottom of the hole to allow the surface to be cleaned and cooled during that period of time in which it is out of engagement with the bottom of the hole, thereby prolonging the life of the bit.

These and other advantages, objects, and features of this invention will be apparent to those skilled in the art from a consideration of this specification, including the attached drawings and appended claims.

In the drawings,

FIG. 1 is a vertical sectional view through the preferred embodiment of the drilling apparatus of this invention; and

FIG. 2 is a side view of the apparatus of FIG. 1.

The apparatus of this invention is for use in rotary drilling procedures to bore a hole in the earth. In operation, it is attached to the lower end of a string of drill pipe that extends to the surface but of which only lower end is shown in FIG. 1. In conventional rotary drilling procedures, drilling mud, either a liquid or gas or a combination of the two, is pumped down through drill pipe 10, out the bottom thereof, and back to the surface through annulus 11 between the drill pipe and well bore 12.

The drilling apparatus of this invention includes drill bit 14. The drill bit comprises body 16 and cutter wheel 18. Body 16 is adapted to be connected to lower end 10 of the drill string. In FIG. 1 it is connected to the drill string through tubular sub 20 and outer housing 22 of a downhole motor to be described below. Thus, bit body 16 is connected to drill string 10 so that rotation of the drill string will be imparted to the drill bit.

Means are provided to mount cutter wheel 18 on drill body 16 for rotation of the cutter wheel around an axis transverse the longitudinal axis of the drill string. In the embodiment shown, shaft 24 is rotatably supported in bearings 26 adjacent opposite ends of the shaft. The bearings in turn are supported by downwardly extending arms 16a and 16b of body 16. These arms were formed by vertical slot 28 that is provided in bit body 16 to accommodate cutter wheel 18. Bearings 26 allow shaft 24 to freely rotate around its longitudinal axis relative to bit body 16.

The longitudinal axis of shaft 24 is transverse and, in the embodiment shown, perpendicular to the longitudinal axis of the drill string. Cutter wheel 18 is mounted on shaft 24 so that it rotates with the shaft around its longitudinal axis and also generally in the plane of the longitudinal axis of the drill string. In other words, cutter wheel 18 is generally centrally located relative to bit body 16so that cutting surface 18a on the outer periphery of the cutting wheel is directly in engagement with the center of the bottom of the well bore.

In the embodiment shown, cutter wheel 18 comprises a matrix in which is embedded a plurality of cutting teeth, such as diamonds, on cutting surface 18a. The wheel is forced to rotate with shaft 24 by keys 30.

Means are provided to rotate cutter wheel 18 around its transverse axis of rotation independent of the rotation thereof by the drill string. In the embodiment shown, turbine 32 is positioned in the drill string between the bottom of drill string 10 and drilling bit 14. The turbine includes outer housing 22, which connects bit body 16 and sub 20 to drill string 10, and central output shaft 34. Turbine blades 36 are alternatively connected to shaft 34 and housing 22, in the conventional manner, so that drilling fluid pumped down through the drill pipe will rotate shaft 34 relative to housing 22. Appropriate bearings, such as bearing 38 and others that are not shown, support shaft 34 for rotation relative to its housing.

Gear means are provided to transmit the rotation imparted to shaft 34 by turbine 32 to cutter wheel 18 causing it to rotate about its transverse axis of rotation independent of drill string rotation. In the embodiment shown, pinion 40 is keyed to the bottom end of shaft 34 for rotation therewith. Mounted on opposite sides of cutter wheel 18 in parallel, spaced relationship are stub or jack shafts 42 and 44. These shafts are supported for rotation by bearings 46 and 48 that are in turn supported in bearing housings 50 and 52, respectively, formed in bit body 16. Gears 54 and 56 are attached to the upper ends of shafts 42 and 44, respectively, to be driven by pinion 40. Rotation of shafts 42 and 44 is transmitted to cutter wheel 18 through bevel gears 58 and 60 attached to the lower end of the shafts and bevel gears 62 and 64 that are keyed to shaft 24 upon which the cutter wheel is mounted.

Section 66 of shaft 34 of the turbine is of enlarged diameter to provide passageways through which the drilling mud can flow as it leaves the turbine. in the embodiment shown, passageways 68 and 70 lead the drilling fluid from opposite sides of the turbine to a common passageway 72, which carries the drilling fluid out the lower end of shaft 34. Passageway 72 is located so that the drilling fluid, as it is discharged from passageway 72, is directed against the outside surface of cutter wheel 18 to clean and cool cutting surface 180 of the wheel during the time that it is out of engagement with the bottom of the hole. In other words, in accordance with this invention, the cutting surface of the cutter wheel, whether it be teeth formed thereon, diamonds or whatever, will be functioning substantially like a grinding wheel or milling cutter normally functions. Thus, about half of the cutting surface will always be unloaded and subjected to the cooling and cleaning action of the drilling fluid discharged from passageway 72. This is particularly advantageous when diamonds or similar hard particles are embedded in the matrix of the cutting wheel to provide the cutting surface. Also, this arrangement causes the entire cutting surface to move across the bottom of the hole at a substantially uniform velocity, thereby making full and uniform use of the entire cutting surface.

From the foregoing it can be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein' set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed is:

l. Drilling apparatus comprising a drilling bit for connecting to the lower end ofa drill string for rotation therewith around the longitudinal axis of the string, said bit including a body, a cutter wheel comprising a disc-shaped member having a continuous, unbroken outer peripheral surface with cutting teeth attached thereto, and means mounting the cutter wheel for rotation relative to the bit body around a transverse axis perpendicular to the axis around which the body is to be rotated by the drill string and with the outer peripheral surface extending laterally equal distances on opposite sides of a plane that includes the said axis of rotation of the body, and motor means located in the drill string above the bit for rotating the cutter wheel around said transverse axis as the bit is rotated by the drill string around the longitudinal axis of the drill string.

2. The drilling apparatus of claim 1 in which the motor means is powered by drilling fluid pumped down the drill string.

3. The drilling apparatus of claim 1 in which the cutting teeth on the cutter wheel are diamonds embedded in its outer peripheral surface.

4. Drilling apparatus comprising a drill string, a turbine located in the drill string adjacent its lower end to be powered by drilling fluid pumped down the drill string, said turbine having an output shaft, a drilling bit including a body attached to the lower end of the drill string for rotation with the drill string around the longitudinal axis of the drill string, a cutter wheel comprising a disc-shaped matrix having a central opening extending laterally therethrough and a plurality of hard abrasive elements, such as diamonds, partially embedded in its continuous, unbroken, outer peripheral surface to act as cutting teeth, a shaft extending through the central opening of the matrix and mounted in the body to support the cutter wheel for rotation with the shaft around a transverse axis that is perpendicular to the longitudinal axis of the drill string with the wheel centrally located with respect to the longitudinal axis of the drill string, and power transmitting means connecting the output shaft of the turbine to the shaft supporting the cutter wheel so the turbine will rotate the cutter wheel around said transverse axis as drilling fluid is pumped down the drill pipe and through the turbine.

5. The apparatus of claim 4 in which the turbine output shaft has a fluid passageway through which the drilling fluid from the turbine flows after it leaves the turbine and which directs the drilling fluid downwardly against the cutter wheel to clean the cutter wheel as it is rotated by the turbine.

6. A drill bit comprising a body for attaching to the lower end of a drill string for rotation therewith as the drill string is rotated around its longitudinal axis, a cutter wheel for cutting away the earth as the drill bit is forced against the bottom of a well bore, means mounting the cutter wheel on the body for rotation around an axis transverse the axis of rotation of the body, and means for transmitting power from a downhole engine carried by the drill string above the bit to rotate the cutter wheel around said transverse axis as the wheel and the body are rotated by the drill string around the longitudinal axis of the drill string, the power transmitting means including two parallel spaced stub shafts mounted for rotation on the body on opposite sides of the cutter wheel, gear means mounted on said shafts for meshing with gear means on the output shaft of said downhole engine whereby rotation of said output shaft will rotate the stub shafts in the same direction, and gear means operatively connecting the stub shafts and the cutter wheel to rotate the cutter wheel around said transverse axis when the stub shafts are rotated by the downhole engine.

7. Drilling apparatus for connecting to the lower end of a drill string for drilling a hole into the earth, said apparatus comprising a fluid powered motor having an outer housing for connecting to the lower end of the drill string for rotation therewith and an output shaft that is rotated by drilling mud pumped down the drill pipe, a drill bit including a body connected to the housing of the motor for rotation with the housing as it is rotated by the drill pipe, a shaft supported by the body with its longitudinal axis intersecting and perpendicular to the axis of rotation of the body, a cutter wheel Inznnn mounted on the shaft for rotation with the shaft relative to the body around the longitudinal axis of the shaft, said cutter wheel comprising a disc-shaped member having a continuous, unbroken outer peripheral surface with cutting teeth attached thereto, and gear means operatively connecting the output shaft of the fluid engine to the shaft supporting the cutter wheel whereby the cutter wheel will be rotated with the shaft around the longitudinal axis of the shaft as drilling mud is pumped down the drill pipe while rotating with the bit housing around the longitudinal axis of the drill string.

8. A drill bit for drilling a well bore in the ground comprising a body for attaching to a drill string for rotation therewith as the drill string is rotated around its longitudinal axis, a cutter wheel comprising a matrix having a continuous, unbroken, peripheral surface to engage the bottom of a well bore in the ground and a plurality of hard, abrasive elements, such as diamonds, partially embedded in the peripheral surface of the cutter wheel to cut away the ground at the bottom of the well borevwhen the cutter wheel is rotated in engagement therewith, means mounting the cutter wheel for rotation around an axis that is perpendicular to the longitudinal axis of the drill string to which the bit is to be attached and centrally located with respect to the outer peripheral surface of the wheel, said means further mounting the cutter wheel for the wheel to be symmetrical with respect to the longitudinal axis of the drill string, when the bit is attached thereto, and power transmission means for transmitting power from the output shaft of a downhole motor located in a drill string above the bit to rotate the cutter around said transverse axis. 

1. Drilling apparatus comprising a drilling bit for connecting to the lower end of a drill string for rotation therewith around the longitudinal axis of the string, said bit including a body, a cutter wheel comprising a disc-shaped member having a continuous, unbroken outer peripheral surface with cutting teeth attached thereto, and means mounting the cutter wheel for rotation relative to the bit body around a transverse axis perpendicular to the axis around which the body is to be rotated by the drill string and with the outer peripheral surface extending laterally equal distances on opposite sides of a plane that includes the said axis of rotation of the body, and motor means located in the drill string above the bit for rotating the cutter wheel around said transverse axis as the bit is rotated by the drill string around the longitudinal axis of the drill string.
 2. The drilling apparatus of claim 1 in which the motor means is powered by drilling fluid pumped down the drill string.
 3. The drilling apparatus of claim 1 in which the cutting teeth on the cutter wheel are diamonds embedded in its outer peripheral surface.
 4. Drilling apparatus comprising a drill string, a turbine located in the drill string adjacent its lower end to be powered by drilling fluid pumped down the drill string, said turbine having an output shaft, a drilling bit including a body attached to the lower end of the drill string for rotation with the drill string around the longitudinal axis of the drill string, a cutter wheel comprising a disc-shaped matrix having a central opening extending laterally therethrough and a plurality of hard abrasive elements, such as diamonds, partially embedded in its continuous, unbroken, outer peRipheral surface to act as cutting teeth, a shaft extending through the central opening of the matrix and mounted in the body to support the cutter wheel for rotation with the shaft around a transverse axis that is perpendicular to the longitudinal axis of the drill string with the wheel centrally located with respect to the longitudinal axis of the drill string, and power transmitting means connecting the output shaft of the turbine to the shaft supporting the cutter wheel so the turbine will rotate the cutter wheel around said transverse axis as drilling fluid is pumped down the drill pipe and through the turbine.
 5. The apparatus of claim 4 in which the turbine output shaft has a fluid passageway through which the drilling fluid from the turbine flows after it leaves the turbine and which directs the drilling fluid downwardly against the cutter wheel to clean the cutter wheel as it is rotated by the turbine.
 6. A drill bit comprising a body for attaching to the lower end of a drill string for rotation therewith as the drill string is rotated around its longitudinal axis, a cutter wheel for cutting away the earth as the drill bit is forced against the bottom of a well bore, means mounting the cutter wheel on the body for rotation around an axis transverse the axis of rotation of the body, and means for transmitting power from a downhole engine carried by the drill string above the bit to rotate the cutter wheel around said transverse axis as the wheel and the body are rotated by the drill string around the longitudinal axis of the drill string, the power transmitting means including two parallel spaced stub shafts mounted for rotation on the body on opposite sides of the cutter wheel, gear means mounted on said shafts for meshing with gear means on the output shaft of said downhole engine whereby rotation of said output shaft will rotate the stub shafts in the same direction, and gear means operatively connecting the stub shafts and the cutter wheel to rotate the cutter wheel around said transverse axis when the stub shafts are rotated by the downhole engine.
 7. Drilling apparatus for connecting to the lower end of a drill string for drilling a hole into the earth, said apparatus comprising a fluid powered motor having an outer housing for connecting to the lower end of the drill string for rotation therewith and an output shaft that is rotated by drilling mud pumped down the drill pipe, a drill bit including a body connected to the housing of the motor for rotation with the housing as it is rotated by the drill pipe, a shaft supported by the body with its longitudinal axis intersecting and perpendicular to the axis of rotation of the body, a cutter wheel mounted on the shaft for rotation with the shaft relative to the body around the longitudinal axis of the shaft, said cutter wheel comprising a disc-shaped member having a continuous, unbroken outer peripheral surface with cutting teeth attached thereto, and gear means operatively connecting the output shaft of the fluid engine to the shaft supporting the cutter wheel whereby the cutter wheel will be rotated with the shaft around the longitudinal axis of the shaft as drilling mud is pumped down the drill pipe while rotating with the bit housing around the longitudinal axis of the drill string.
 8. A drill bit for drilling a well bore in the ground comprising a body for attaching to a drill string for rotation therewith as the drill string is rotated around its longitudinal axis, a cutter wheel comprising a matrix having a continuous, unbroken, peripheral surface to engage the bottom of a well bore in the ground and a plurality of hard, abrasive elements, such as diamonds, partially embedded in the peripheral surface of the cutter wheel to cut away the ground at the bottom of the well bore when the cutter wheel is rotated in engagement therewith, means mounting the cutter wheel for rotation around an axis that is perpendicular to the longitudinal axis of the drill string to which the bit is to be attached and centrally located with Respect to the outer peripheral surface of the wheel, said means further mounting the cutter wheel for the wheel to be symmetrical with respect to the longitudinal axis of the drill string, when the bit is attached thereto, and power transmission means for transmitting power from the output shaft of a downhole motor located in a drill string above the bit to rotate the cutter around said transverse axis. 